1. Field of the Invention
The present invention relates to a structure for mounting an armrest in an automotive seat, and is in particular directed to the armrest mounting structure in the seat of type having a fore-and-aft movable seat cushion frame and a seat back frame connected pivotally with the seat cushion frame, with the arrangement that fore-and-aft movement of seat back frame causes angular variation of seat cushion frame relative thereto, and wherein the armrest is pivotally connected to the lower frame section of seat back frame such as to be rotatable between a use position projecting forwardly of the seat and a non-use position resting on the seat back.
2. Description of Prior Art
FIGS. 1 and 2 illustrate an example of conventional armrest mounting structure wherein a seat cushion frame (CF) is of a type movable forwardly and backwardly, forming a seat cushion (SC), and a seat back frame (BF), which forms a seat back (SB), is pivotally connected with the seat cushion frame (CF) such as to be rotatable forwardly and backwardly relative thereto, for allowing inclination angle adjustment of the seat back frame (BF), wherein an an armrest (A) is pivotally connected on the lower side of lower frame section (BF1) of seat back frame (BF). According to this structure, for example, when the seat cushion (SC) is moved forwardly, the upper part of seat back (SB) is lowered along a cabin wall (F) of automobile, while being rotated about the pivot point to vary its inclination angle. Designations (X)(X) denote a pair of bearing members on which the seat back frame (BF) is mounted in a manner to be slidable vertically and rotatable thereabout.
The seat back frame (BF), as viewed from FIG. 2, is formed by the lower frame section (BF1), a right-side part (BF2) thereof, a righ-side lateral frame section (BF4) whose lower end (BF3) is fixed to the right-side part (BF2) of lower frame section (BF1), an upper frame section (BF7), wherein the upper end (BF5) of right-side lateral frame section (BF4) is fixed to the upper frame section (BF7), and a pair of spaced-apart intermediate frame sections (BF12)(BF13) which are extended between the upper and lower frame sections (BF7)(BF1). With regard to the two intermediate frame sections (BF12)(BF13), taking one (BF12) of them for example, its upper part (BF10) and lower part (BF11) are fixed to the left-side end part (BF8) of upper frame section (BF7) and left-side end part (BF9) of lower frame section (BF1).
As seen in FIG. 2, there are a pair of spaced-part forwardly projected arms (B1)(B2), such that the left-side arm (B1) is fixed to a point of the lower frame left-side end part (BF9) to which the lower end (BF11) of left-side intermediate frame section (BF12) is fixed in a manner orthogonal relative thereto, and that the right-side arm (B2) is fixed to a point of the same part (BF9) to which the lower end (BF14) of right-side intermediate frame section (BF13) is likewise fixed orthogonally relative thereto.
As indicated by the phantom line, armrest body (A) is at its rearward end part pivotally supported by the two arms (B1)(B2), such that the armrest body (A) may be moveable between a use position to project generally horizontally for receiving arm of an occupant sitting on the seat and a non-use storage position to be stored in the central storage section in the seat back (SB).
The lower frame section (BF1) is formed with a pair of spaced-apart downwardly projected connecting arms (BF15)(BF15), such that left-side one of the connecting arms is located between the two armrest support arms (B1)(B2) at the left-side end area (BF9) of the lower frame section (BF1), whereas right side one of them is located at the right-side end area (BF2) of the same (BF1).
The seat cushion frame (CF) has a pair of spaced-apart connecting arms (CF1)(CF1) such as to extend in correspondence with the respective two connecting arms (BF15)(BF15) associated with the seat back frame (BF). Those connecting arms (CF1)(BF15) are pivotally connected together in a mutually rotatable way.
Designations (BP) and (CP) denote a seat back padding of seat back (SB) and a seat cushion padding of seat cushion (SC), respectively.
With the above-described conventional armrest mounting structure, however, it has been found as a problem that an entire weight or load of the armrest body (A) is directly transmitted through the arms (B1)(B2) to the left-side end area (BF9) of lower frame section (BF1) which is only supported by the connecting arms (BF15)(CF1). As a result, in view of the two intermediate frame sections (BF12)(BF13) of a thin wire material being simply welded to such left-side end area (BF9), the lower frame section (BF1) is week in strength against the weight of the armrest body (A), and thus such trouble has occured, that the armrest body (A) is unstably moved or wobbled, giving an uneasy feeling to the arm of an occupant sitting on the seat.